Apparatus for polishing hollow metal ware



Oct. 12 1926. 1,602,660

M. GROENINGER APPARATUS FOR POLISHING HOLLOW METAL WARE Filed Dec. 11, 1923 "til Patented Oct. 12, 1926.

MATHAI EUS GROENINGER, OF BASEL, SWITZERLAND.

APPARATUS FOR POLISHING HOLLOW METAL WARE.

Application filed December 11, 1923, Serial No. 679,988, and in France December 22, 1922.

This invention consists in an improved apparatus for polishing hollow metal ware, more especially hollow aluminum ware.

The known process of polishing solid cast articles, such as forks, spoons and the like, consists in enclosing these articles with a large number of small balls in a rotatable drum containing an aqueous solution of soap, and rotating the drum for some time. This process is not suitable for easily deformed hollow ware, as in this case the hollow ware to be polished becomes deformed owing to its position changing and masses of balls knocking against it, or at least becomes dented or marked by the impact of the balls thereon.

These defects are according to the present invention obviated by enclosing the articles to be polished in a perforated or wire-mesh drum arranged within a larger rotatable closed drum in which the polishing balls and a polishing liquid are placed, the arrangement being such that the articles to be polished are subjected to the polishing action of the balls without being damaged by being pounded upon by masses of balls.

Said inner drum may be stationary relatively to the outer drum, i. c. it may be fixed to it and rotate with it in the same direction and at the same speed; or the speed of the inner drum may be independent of that of the outer drum, and the drums may rotate in opposite directions. The speed of the inner drum in this case should be considerably less than that of the outer drum.

If the inner drum does not rotate relatively to the outer drum, articles to be polished which are provided with a bottom are preferably enclosed in individual cages which are placed within the inner drum. A number of small articles may be enclosed in one cage. If the inner drum rotates independently of and in the opposite direction to the outer drum, such cages are found to be unnecessary.

To increase the efficiency of the polishing action of the balls, they should be guided as far as possible'towards theaxis of the iner cylinder.

Apparatus according to the invention is illustrated in the accompanying drawing,

:1 which Fig. 1 is a longitudinal section of a polishing drum having an inner drum fixed there- 1n.

Fig. 2 is also a longitudinal section of another constructional form, in which the inner drum rotates independently of the outer drum.

Fig. 8 is a cross section.

Figs. 4: and 5 show in plan and elevation a constructional form of the wire cages, in which several single cages are combined to form a unit.

In the drawing the outer drum a is shown as hexagonal in cross section. Its shaft 5 is carried in bearings c and provided with a driving pulley (Z. in Fig. 1 the inner drum 6 is fixed to the outer drum and consists of a frame f covered with wire netting or the like. The articles to be polished are introduced into the inner drum through an aperture It which is afterwards closed.

In the constructional form shown in Figs. 2 and 3 the inner drum rotates in the direc tion indicated by the arrow 2, and the outer drum rotates in the opposite direction, as indicated by the arrow 1 (Fig. The shaft 2' of the inner drum passes through the hollow shaft 5 of the outer drum and a stufiing box 70, and it is provided with a driving pulley Z.

Within the outer drum a several ledges m are provided. These ledges are inclined in the direction of rotation of the outer drum a so that they form an acute angle with the wall of the said drum; they carry the balls upwards as they rotate and discharge them upon the periphery of the inner drum, directing them towards its axis and thus increasin the polishing power of the balls.

I claim:

1. In apparatus for polishing hollow metal ware by means of polishing balls and a polishing liquid, the combination of a plain outer drum adapted to receive the polishing balls and liquid, and provided with inclined longitudinal ledges on its inner periphery, a perforated inner drum arranged coaxially within said outer drum and adapted to receive the articles to be polished, and means for rotating the said drums, substantiall as described.

2. In apparatus for polishing hollow metal ware by means of polishing balls and In the construction shown polished and means for rotating each of the said druins independently, substantially as described.

In testimony whereof I signed hereunto my name.

MATHAEUS GROENINGER. 

